Conduction structure, method of manufacturing conduction structure, droplet ejecting head, and printing apparatus

ABSTRACT

A conduction structure includes a device substrate (first substrate), an IC (second substrate) having an upper surface and an end surface, a sealing plate (third substrate) having an upper surface and an end surface, a conductive layer having a first part provided on an upper surface of the device substrate, a second part provided on the end surface of the IC and connected to the first part, a third part provided on the upper surface of the IC and connected to the second part, and a fourth part provided on the end surface of the sealing plate and connected to both of the first part and the second part, and a plating layer overlapped with the conductive layer.

BACKGROUND

1. Technical Field

The present invention relates to a conduction structure, a method ofmanufacturing a conduction structure, a droplet ejecting head, and aprinting apparatus.

2. Related Art

A printing apparatus including a droplet ejecting head is used whenprinting is performed on a recording medium such as printing paper (forexample, see JP-A-2006-289943).

The droplet ejecting head disclosed in JP-A-2006-289943 includes a flowchannel forming substrate in which a pressure generating chamber thattemporarily stores ink and an ejection port that communicates with thepressure generating chamber and ejects ink in the pressure generatingchamber as droplets are formed, and a reservoir forming substrate whichis provided on the flow channel forming substrate, and in which aportion of a reservoir that preliminarily maintains ink to be suppliedto the pressure generating chamber is formed. Also, a piezoelectricelement adjacent to the pressure generating chamber is arranged. Thepiezoelectric element is electrically connected to a driver IC thatcontrols the driving of the piezoelectric element via a wiring pattern(conduction structure). Also, it is possible to securely eject inkdroplets from the ejection port by driving the piezoelectric element.

Here, the piezoelectric element is provided in a space called apiezoelectric element maintaining portion provided on the flow channelforming substrate. Also, the wiring pattern connecting the piezoelectricelement and the driver IC is constructed along the inclination surfaceprovided on the flow channel forming substrate. The wiring pattern(conduction structure) connecting between the piezoelectric element andthe driver IC is formed by various methods. For example,JP-A-2006-289943 employs a method of bonding the reservoir formingsubstrate and the driver IC while the position of electric wiringconstructed on the inclination surface and the mounting surface of thedriver IC and positions of connection terminals of the driver IC arematched, and then depositing plating metal on electric wiring on boththe reservoir forming substrate side and connection terminals on thedriver IC side by an electroless plating method. Then, the electricwiring of the reservoir forming substrate and the connection terminal ofthe driver IC are electrically bonded by depositing plating metal onboth until the both are bonded each other.

Meanwhile, JP-A-2005-311122 and JP-A-2006-140247 disclose a method ofarranging the semiconductor device on the wiring substrate andelectrically connecting the wiring substrate and the semiconductordevice by growing plating metal from both the connection terminal of thewiring substrate and the connection terminal of the semiconductor deviceby the electroless plating method.

However, in the method disclosed in JP-A-2006-289943, the position ofthe electric wiring provided on the reservoir forming substrate and theposition of the connection terminal of the driver IC have to becorrectly matched. Therefore, as the arrangement density of the electricwiring provided on the reservoir forming substrate and the arrangementdensity of the connection terminal provided on the driver IC increase,the time required for the adhesion of the driver IC increases.Therefore, it is difficult to reduce the size of the droplet ejectinghead.

Meanwhile, in the method disclosed in JP-A-2005-311122 andJP-A-2006-140247, electric connection is obtained by using plating metalisotropically grown by an electroless plating method in the state inwhich the connection terminal of the wiring substrate and the connectionterminal of the semiconductor device are separated from each other, andjoining plating metal between the connection terminals separated fromeach other.

Since the plating metal isotropically grows as described above, when theplating metal is grown so as to join the connection terminals separatedfrom each other, the plating metal widely expands at the same time inthe width direction of the wiring pattern which is formed by plating(direction orthogonal to direction in which connection terminals to bejoined are connected). Therefore, in order to prevent an unintendedshort circuiting, the adjacent connection terminals in the wiringsubstrate, or the adjacent connection terminals in the semiconductordevice have to be separated from each other. As a result, thearrangement density of the connection terminals cannot be sufficientlyincreased, and it is difficult to reduce the size of the wiringsubstrate or the semiconductor device.

SUMMARY

An advantage of some aspects of the invention is to provide a conductionstructure that can easily cause wires between substrates to be disposedat high density and can be easily manufactured, an effective method ofmanufacturing a conduction structure, a droplet ejecting head thatincludes the conduction structure and can easily cause the size thereofto be reduced, and a printing apparatus including the droplet ejectinghead.

An aspect of the invention is directed to a conduction structureincluding a first substrate that has a main surface, and includes aterminal portion for performing electric connection; a second substratethat has a main surface and an end surface continued to the main surfacein a non-parallel manner so that the main surface thereof is fixed tothe main surface of the first substrate by adhesion so as to face themain surface of the first substrate, and includes a terminal portion forperforming electric connection; and a conductive layer of which at leasta portion is provided on the end surface so as to connect the terminalportion of the first substrate and the terminal portion of the secondsubstrate so that the first substrate and the second substrate arecoupled.

With this configuration, since the first substrate and the secondsubstrate are electrically connected by using the end surface, and whenthe arrangement density of the wiring to be formed is high, the wiringcan be effectively and correctly formed. Also, if the conductive layeris used as the ground of the plating, it is possible to form the platinglayer while maintaining the shape of the conductive layer, andaccordingly it becomes easy to suppress the increase of the electricalresistance, so it is possible to allow the wiring to be fine.Accordingly, it is possible to obtain the conduction structure that caneasily cause the wiring between substrates to be disposed at highdensity and that can be easily manufactured.

In the conduction structure according to the aspect of the invention, itis preferable that an angle formed between the main surface and the endsurface in the second substrate is greater than 0° and less than 90°.

With this configuration, it is possible to reduce the size of theconduction structure, and to easily form the conductive layer on the endsurface.

In the conduction structure according to the aspect of the invention, itis preferable that the conduction structure further includes a platinglayer that is overlapped with at least a portion of the conductivelayer.

With this configuration, the wiring pattern including two layers whichare the conductive layer and the plating layer is formed, and thereforeit is possible to reduce the electrical resistance. It is possible toeasily cause the wiring pattern to be finely formed, and therefore it ispossible to cause the wiring pattern to be denser.

In the conduction structure according to the aspect of the invention, itis preferable that the second substrate is made of silicon as a mainmaterial.

With this configuration, if the second substrate is an IC, theperformance is excellent. Further, if the first substrate is also madeof silicon as a main material, the thermal expansions of the firstsubstrate and the second substrate are close to each other. Therefore,it is possible to suppress the generation of a defect such as adistortion in the conduction structure.

In the conduction structure according to the aspect of the invention, itis preferable that the end surface of the second substrate is configuredwith a plane of (1, 1, 1) silicon surface orientation.

With this configuration, it is possible to enhance the accuracy of theinclination angle to the main surface and enhance the planarization ofthe end surface. As a result, it is possible to enhance the arrangementdensity of the wiring when the conductive layer and the plating layerare formed on the end surface as the wiring.

In the conduction structure according to the aspect of the invention, itis preferable that in the first substrate, the terminal portion isprovided on the main surface, in the second substrate, the terminalportion is provided on the main surface, and the conductive layerincludes a first part provided on the main surface of the firstsubstrate, a second part that is provided on the end surface of thesecond substrate and is electrically connected to the first part, and athird part that is provided on the main surface of the second substrateand is electrically connected to the second part.

With this configuration, since it is possible to electrically connectthe terminal portions by using the end surface, it is possible toenhance the reduction of the size of the conduction structure and themanufacturability of the conduction structure. Also, since the firstpart, the second part, and the third part of the conductive layer can beeasily recognized in one direction, the inspection of these partsbecomes easy.

In the conduction structure according to the aspect of the invention, itis preferable that the conduction structure further includes a thirdsubstrate that has a main surface and an end surface continued to themain surface in a non-parallel manner and is provided between the firstsubstrate and the second substrate, and the conductive layer includes afourth part that is provided on the end surface of the third substrate,and is electrically connected to both of the first part and the secondpart.

With this configuration, it is possible to form wiring that connectsfrom the first substrate to the second substrate with the thirdsubstrate interposed therebetween, and it is possible to cause thewiring to be disposed at high density, and to have low electricalresistance at the same time.

In the conduction structure according to the aspect of the invention, itis preferable that the end surface of the second substrate and the endsurface of the third substrate are positioned on the same surface.

With this configuration, if the conductive layer is formed by aphotolithographic method, since the second part and the fourth part caneasily satisfy the exposure condition, it is possible to easily increasethe accuracy of the patterning. Accordingly, it is possible to enhancethe dimensional accuracy of the wiring so that the arrangement densityof the wiring can be enhanced.

In the conduction structure according to the aspect of the invention, itis preferable that the end surface of the second substrate and the endsurface of the third substrate are positioned in a deviated manner, andthe conductive layer further includes a fifth part that is provided onthe main surface of the third substrate, and is electrically connectedto both the second part and the fourth part.

With this configuration, for example, if the conductive layer isprovided on the main surface of the third substrate, the conductivelayer provided on the main surface of the third substrate and the fifthpart can securely come into contact with each other so that theelectrical connection between the conductive layer provided on the mainsurface of the third substrate and the wiring can be achieved. Inaddition, if the electric connection between the conductive layerprovided on the main surface of the third substrate and the wiring isachieved, it is not necessary to extend the conductive layer provided onthe main surface of the third substrate to the end surface side.Therefore, it is advantageous in that the electric connection can beeasily established.

In the conduction structure according to the aspect of the invention, itis preferable that the third substrate includes an electric circuitelectrically connected to the fifth part.

With this configuration, for example, even if the electronic circuit isformed on the third substrate, it is possible to improve the reliabilityof the electric connection between the electronic circuit and thewiring. Therefore, it is possible to enhance the operation stability ofthe electronic circuit.

Another aspect of the invention is directed to a method of manufacturinga conduction structure including a first substrate that has a mainsurface and includes a terminal portion for performing electricconnection, a second substrate that has a main surface and an endsurface continued to the main surface in a non-parallel manner so thatthe main surface is fixed to the first substrate by adhesion so as toface the main surface of the first substrate and includes a terminalportion for performing electric connection, and a conductive layer thatconnects the terminal portion of the first substrate and the terminalportion of the second substrate so that the first substrate and thesecond substrate are coupled. The method includes adhering the firstsubstrate and the second substrate together so that the main surface ofthe first substrate and a portion of the main surface of the secondsubstrate face each other and the other portion of the main surface ofthe second substrate protrudes; obtaining a metallic film by forming afilm with a metallic material on the terminal portion of the firstsubstrate, the end surface of the second substrate, and the terminalportion of the second substrate; and obtaining the conductive layer bypatterning the metallic film.

With this configuration, it is possible to manufacture the conductionstructure that can easily cause the wiring between substrates to bedisposed at high density and that can be easily manufactured.

In the method of manufacturing a conduction structure according to theaspect of the invention, it is preferable that the end surface of thesecond substrate is a surface formed by anisotropic etching.

With this configuration, it is possible to easily form an angle betweena surface to be processed (end surface) and the main surface of the basematerial which is a work piece as designed. Therefore, it is possible toeasily perform the processing into a desired shape, and it is possibleto form the inclination angle of the end surfaces to be close to theshape as designed.

In the method of manufacturing a conduction structure according to theaspect of the invention, it is preferable that the metallic film isformed by a sputtering method, and the conductive layer is obtained bypatterning the metallic film by a photolithographic method.

In the sputtering method, since it is possible to form a metallic filmhaving a high adhesive property at a comparatively low temperature, theheat effect on the first substrate and the second substrate followed bythe film formation is suppressed to the minimum, to contribute to therealization of the conduction structure with high accuracy. Also, sincethe control of the film thickness is comparatively easy, it is possibleto obtain the metallic film which is highly uniform in thickness.Finally, it is possible to enhance the accuracy in patterning thewiring, and to contribute to the formation of the wiring to be at highdensity.

In the method of manufacturing a conduction structure according to theaspect of the invention, it is preferable that the conduction structurefurther includes a plating layer that is overlapped with at least aportion of the conductive layer, and the method of manufacturing theconduction structure further includes depositing the plating layer onthe conductive layer by a plating method.

With this configuration, since it is possible to decrease the electricalresistance of the conduction structure, it is possible to cause thewiring pattern to be finer and at high density.

In the method of manufacturing a conduction structure according to theaspect of the invention, it is preferable that the plating method is anelectroless plating method.

With this configuration, it is possible to selectively deposit metal onthe conductive layer, and it is possible to easily form the platinglayer.

Still another aspect of the invention is directed to a droplet ejectinghead including the conduction structure according to the aspect of theinvention.

With this configuration, it is possible to obtain a droplet ejectinghead which is small and has high reliability.

Yet another aspect of the invention is directed to a printing apparatusincluding the droplet ejecting head according to the aspect of theinvention.

With this configuration, it is possible to obtain a printing apparatuswhich is small and has high reliability.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be described with reference to the accompanyingdrawings, wherein like numbers reference like elements.

FIG. 1 is a cross-sectional view illustrating a droplet ejecting head towhich a conduction structure according to the first embodiment of theinvention is applied (droplet ejecting head according to firstembodiment of the invention).

FIG. 2 is a diagram illustrating a droplet ejecting head viewed in thedirection of an arrow A illustrated in FIG. 1 (plan view).

FIG. 3 is an enlarged and detailed view illustrating an area Bsurrounded by a dashed line in FIG. 2.

FIG. 4 is an enlarged and detailed view illustrating an area Csurrounded by a dashed line in FIG. 1.

FIGS. 5A to 5C are cross-sectional views illustrating a method ofmanufacturing the conduction structure according to the firstembodiment.

FIGS. 6A to 6C are cross-sectional views illustrating the method ofmanufacturing the conduction structure according to the firstembodiment.

FIG. 7 is a perspective view illustrating a printing apparatus accordingto an embodiment of the invention.

FIG. 8 is an enlarged cross-sectional view illustrating a part of adroplet ejecting head to which a conduction structure according to asecond embodiment of the invention is applied (droplet ejecting headaccording to second embodiment of the invention).

FIG. 9 is an enlarged cross-sectional view illustrating a part of adroplet ejecting head to which a conduction structure according to athird embodiment of the invention is applied (droplet ejecting headaccording to third embodiment of the invention).

FIG. 10 is an enlarged cross-sectional view illustrating a part of asemiconductor apparatus to which a conduction structure according to afourth embodiment of the invention is applied.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

Hereinafter, a conduction structure, a method of manufacturing theconduction structure, a droplet ejecting head, and a printing apparatusaccording to the invention are described with reference to the preferredembodiments illustrated in the accompanying drawings.

First Embodiment

Droplet Ejecting Head and Conduction Structure

FIG. 1 is a cross-sectional view illustrating a droplet ejecting head towhich a conduction structure according to the first embodiment of theinvention is applied (droplet ejecting head according to the firstembodiment of the invention), FIG. 2 is a diagram illustrating a dropletejecting head viewed in the direction of an arrow A illustrated in FIG.1 (plan view), FIG. 3 is an enlarged and detailed view illustrating anarea B surrounded by a dashed line in FIG. 2, FIG. 4 is an enlarged anddetailed view illustrating an area C surrounded by a dashed line in FIG.1, FIGS. 5A to 6C are cross-sectional views illustrating a method ofmanufacturing the conduction structure according to the firstembodiment, and FIG. 7 is a perspective view illustrating a printingapparatus according to an embodiment of the invention. Hereinafter, forconvenience of the description, upper sides of FIGS. 1 and 4 to 6C arereferred to as “up” or “upper”, and lower sides thereof are referred toas “under” or “lower”.

A droplet ejecting head 1 illustrated in FIGS. 1 to 4 includes a basesubstrate 2 configured with a plate body, and an integrated circuit (IC)9 arranged on the base substrate 2. The droplet ejecting head 1 ismounted on a printing apparatus (droplet ejecting apparatus) 100 asdescribed below, and can perform printing on a recording medium 200 byejecting ink 300 onto the recording medium 200 such as printing paper asdroplets (see FIG. 7).

As illustrated in FIG. 2, the base substrate 2 has a rectangular shapein a plan view. The base substrate 2 includes a sealing plate 10A, adevice substrate 10B, and a nozzle substrate (nozzle plate) 21, and isconfigured with a stacked body in which the nozzle substrate 21, thedevice substrate 10B, and the sealing plate 10A are stacked in thissequence from the lower side. In addition, the sealing plate 10A and thedevice substrate 10B are bonded via an adhesive layer (adhesive agent)11. The sealing plate 10A and the device substrate 10B are arranged sothat the upper surface of the device substrate 10B and the lower surfaceof the sealing plate 10A face each other, and are bonded so that theadhesive layer 11 is interposed therebetween.

Meanwhile, the IC 9 and the sealing plate 10A are bonded via an adhesivelayer (adhesive agent) 14. Then, the IC 9 and the sealing plate 10A arearranged so that the upper surface of the sealing plate 10A and thelower surface of the IC 9 face each other, and are bonded so that theadhesive layer 14 is interposed therebetween.

The device substrate 10B, the sealing plate 10A, and the IC 9 accordingto the second and third embodiments of the invention to be describedbelow all have plate shapes which extend in the horizontal direction ofFIG. 4. Therefore, in the descriptions according to the second to thirdembodiments, among two main surfaces included in each of the devicesubstrate 10B, the sealing plate 10A, and the IC 9, a main surfacepositioned on the upper side of FIG. 4 is referred to as an “uppersurface”, and the other main surface positioned on the lower side isreferred to as a “lower surface”.

Thicknesses of the adhesive layers 11 and 14 are not particularlylimited, and may be, for example, in the range of 0.5 μm to 5 μm, andpreferably in the range of 1 μm to 2 μm. In addition, the devicesubstrate 10B and the nozzle substrate 21 are bonded together via theadhesive layer (not illustrated).

The sealing plate 10A is configured with a stacked body in which areservoir forming substrate (protection substrate) 24 and a compliancesubstrate 26 are included, and are stacked from the lower side in thissequence. Also, the device substrate 10B is also configured with astacked body in which a flow channel forming substrate 22, a diaphragm23, and a plurality of piezoelectric elements 25 are included, and arestacked from the lower side in this sequence. Also, in the respectivestacked bodies, respective layers that configure the stacked bodies arebonded via adhesive layers or heat welding films (not illustrated).

Since the base substrate 2 is configured with the stacked body, therespective layers that configure the stacked body can be used accordingto the purposes and functions thereof. Accordingly, the thin dropletejecting head 1 can be obtained, and the size of the printing apparatus100 can be reduced.

The nozzle substrate 21 as illustrated in FIG. 1 has a plurality ofejection ports (nozzle openings) 211 that are formed to penetrate thenozzle substrate 21, that is, to be open to a lower surface 212 of thebase substrate 2 (plate body). The ejection ports 211 are arranged in amatrix shape. One or more ejection ports 211 according to the presentembodiment are arranged in a longitudinal direction (long sidedirection) of the base substrate 2, and two columns are arranged in thewidth direction (short side direction).

It is preferable that water repellent coating layers be provided on therespective ejection ports 211. Accordingly, the droplets ejected fromthe respective ejection ports 211 easily fall in the vertical direction,and can correctly land on the positions at which the droplets shouldland on the recording medium 200.

Further, the configuration materials of the nozzle substrate 21 are notparticularly limited, but a silicon material or stainless steel ispreferably used. Since these materials have high resistance tochemicals, even if the materials are exposed to the ink 300 for a longtime, the alteration or the deterioration of the nozzle substrate 21 canbe securely prevented. Also, since the materials have high workability,the nozzle substrate 21 with high dimensional accuracy can be obtained.Therefore, a highly reliable droplet ejecting head 1 can be obtained.

Flow channels (cavities) 221 that cause the ink 300 to flow to therespective ejection ports 211 are formed in the flow channel formingsubstrate 22. The flow channels 221 are formed, for example, by etching.As illustrated in FIG. 1, the flow channels 221 can each be divided intoa pressure generating chamber 222, a relay chamber (communicationportion) 223, and a communication route (supply route) 224 that causesthe pressure generating chamber 222 and the relay chamber 223 tocommunicate with each other.

The pressure generating chamber 222 is provided to correspond to therespective ejection ports 211, and communicates with the outside via thecorresponding ejection ports 211.

The relay chamber 223 is provided on the upper stream side of thepressure generating chamber 222.

Also, the communication route 224 is provided between the pressuregenerating chamber 222 and the relay chamber 223.

The configuration material of the flow channel forming substrate 22 isnot particularly limited, and for example, may use the sameconfiguration material as the nozzle substrate 21.

The diaphragm 23 can vibrate in the thickness direction by driving thepiezoelectric elements 25 described below. Also, a portion of thediaphragm 23 comes into contact with the pressure generating chamber222. The pressure in the pressure generating chamber 222 changes due tothe vibration of the diaphragm 23 so that the ink 300 is ejected asdroplets from the pressure generating chamber 222 via the ejection ports211.

The diaphragm 23 is obtained by sequentially stacking an elastic film231 and the lower electrode film 232 from the flow channel formingsubstrate 22 side. The elastic film 231 is configured with a siliconoxide film having a thickness, for example, in the range of 1 μm to 2μm. The lower electrode film 232 is configured with a metal film havinga thickness, for example, of about 0.2 μm. The lower electrode film 232also functions as common electrodes of the plurality of piezoelectricelements 25 arranged between the flow channel forming substrate 22 andthe reservoir forming substrate 24.

In the reservoir forming substrate 24, reservoirs 241 that temporarilystore the ink 300 are formed to communicate with the respective flowchannels 221 of the flow channel forming substrate 22. As illustrated inFIG. 1, the reservoirs 241 each include a first chamber (reservoirportion) 242, a second chamber (introduction route) 243, and acommunication route 244 that cause the first chamber 242 and the secondchamber 243 to communicate with each other.

The first chamber 242 is positioned on the upper portion of the relaychamber 223 of the flow channels 221 in the flow channel formingsubstrate 22. Also, the diaphragm 23 is penetrated at a portion betweenthe first chamber 242 and the relay chamber 223 so that the firstchamber 242 and the relay chamber 223 communicate with each other.

The second chamber 243 is provided on the upper stream side of the firstchamber 242.

The communication route 244 is provided between the first chamber 242and the second chamber 243.

Also, in the droplet ejecting head 1, the relay chamber 223 mayconfigure a portion of the reservoirs 241.

Also, piezoelectric element receiving chambers 245 that each receive thepiezoelectric element 25 are formed in the reservoir forming substrate24. The piezoelectric element receiving chambers 245 are formed to beseparated from the reservoirs 241.

The configuration materials of the reservoir forming substrate 24 arenot particularly limited, and may use, for example, silicon or glass.

The respective piezoelectric elements 25 are formed by stacking apiezoelectric film (piezo element) 251 and an upper electrode film 252sequentially from the lower electrode film 232 side. When the voltage isapplied between the upper electrode film 252 and the lower electrodefilm 232, the piezoelectric film 251 is deformed by the piezoelectriceffect. According to the deformation, the diaphragm 23 vibrates in thevertical direction. As described above, the pressure in the pressuregenerating chamber 222 is changed due to the vibration of the diaphragm23 so that the ink 300 can be ejected from the corresponding pressuregenerating chamber 222 via the ejection ports 211 as droplets. Asdescribed above, the respective piezoelectric elements 25 are configuredso as to eject the ink 300 (droplet) from the respective ejection ports211 via the diaphragm 23.

The compliance substrate 26 is formed by stacking a sealing film 261 anda fixing plate 262 sequentially from the reservoir forming substrate 24side. The sealing film 261 is configured with a flexible material (forexample, a polyphenylene sulfide film having a thickness of about 6 μm).A portion of the sealing film 261 comes into contact with the reservoir241. Also, the fixing plate 262 is configured with a comparatively hardmaterial (for example, stainless steel having a thickness about 30 μm)such as a metallic material. In the fixing plate 262, a portion thatcomes into contact with the reservoirs 241 side, and defective portions263 in which the corresponding portion is defective are formed.

Introduction ports 264 that penetrate the sealing film 261 and thefixing plate 262 together are formed on the compliance substrate 26. Theintroduction ports 264 are portions that respectively communicate withthe reservoirs 241, and introduce the ink 300 to the correspondingreservoirs 241.

A concave portion 27 that is open toward a central portion of an uppersurface 265 of the sealing plate 10A (the compliance substrate 26) asillustrated in FIG. 1 is formed in the base substrate 2 configured withthe stacked body as described above. The concave portion 27 is formed bycutting the sealing plate 10A by etching until the sealing plate 10A ispenetrated in the thickness direction.

As illustrated in FIGS. 1 and 2, the concave portion 27 has a grooveshape along the longitudinal direction of the base substrate 2. Also,the concave portion 27 includes a bottom portion 271, first side wallportions (side wall portions) 272 a and 272 b that stand from the bottomportion 271, and face each other in the width direction (intersectingdirection) of the concave portion 27 (groove), and second side wallportions 273 a and 273 b that stand from the bottom portion 271, andface each other in the longitudinal direction of the concave portion 27.

In a concave portion 270, the bottom portion 271 becomes a flat portion.

In addition, the first side wall portions 272 a and 272 b are inclinedtoward the bottom portion 271 (and the upper surface 265 of the sealingplate 10A). Further, the inclination angle is not particularly limited,but if the reservoir forming substrate 24 is configured with silicon,the inclination angle can be appropriately set according to the surfaceorientation, and an inclination angle of 54.7° or 35.7° can be easilyformed. In addition, the first side wall portion 272 a and the firstside wall portion 272 b are configured so that the separation distancegradually increases moving to the upper surface 265 side.

The second side wall portion 273 a and the second side wall portion 273b are also inclined toward the bottom portion 271 in the same manner asthe first side wall portions 272 a and 272 b. Also, the second side wallportion 273 a and the second side wall portion 273 b are configured sothat the separation distance gradually increases moving to the uppersurface 265 side.

In this manner, since the first side wall portions 272 a and 272 b andthe second side wall portions 273 a and 273 b are inclined respectively,when the concave portion 27 is formed, for example, by etching, theformation can be performed easily and securely.

In other words, the bottom portion 271 is a portion corresponding to theupper surface of the device substrate 10B. Also, the first side wallportions 272 a and 272 b, and the second side wall portions 273 a and273 b are configured including end surfaces of the sealing plate 10A.The end surfaces continue to the upper surface and the lower surface ofthe sealing plate 10A, and are inclined to the upper surface and thelower surface as described above. According to the first embodiment, aportion of the upper electrode film 252 positioned on the bottom portion271 corresponds to a “terminal portion” included in the device substrate10B.

As illustrated in FIG. 1, the IC 9 includes an electronic circuit (notillustrated) formed on a semiconductor substrate and a plurality ofterminals (terminal portions) 93 electrically connected to theelectronic circuit.

According to the first embodiment, two ICs 9 are arranged with theconcave portion 27 interposed therebetween as illustrated in FIGS. 1 to3.

The IC 9 uses various semiconductor materials such as silicon,germanium, or a compound semiconductor material, as a main material, andamong them silicon is preferably used as the main material. Since the IC9 including silicon as the main material has an excellent performanceand a thermal expansion which is similar to that of the reservoirforming substrate 24, the generation of a distortion can be suppressed.

As described above, a lower surface 91 of the IC 9 is bonded to theupper surface 265 of the sealing plate 10A via the adhesive layer 14.Also, an upper surface 92 of the IC 9 is substantially parallel to thelower surface 91.

Meanwhile, an end surface 94 a of the IC 9 is positioned on the samesurface with the first side wall portion 272 a of the sealing plate 10Adescribed above, as illustrated in FIG. 4. Also, an end surface 94 b ofthe IC 9 which is different from the IC 9 described above is provided ata position facing the end surface 94 a in the width direction of theconcave portion 27. As illustrated in FIG. 1, the end surface 94 b isalso positioned on the same surface with the first side wall portion 272b of the sealing plate 10A described above.

As illustrated in FIG. 4, the end surfaces 94 a and 94 b may not beparallel to the lower surface 91 of the IC 9. That is, angles formed bythe end surfaces 94 a and 94 b with the lower surface 91 must be greaterthan 0°.

In addition, the angle formed by the end surfaces 94 a and 94 b with thelower surface 91 may be 90° (right angle). However, in order to reducethe size of the droplet ejecting head 1, it is preferable that theangles formed by the end surfaces 94 a and 94 b with the lower surface91 be respectively less than 90°, that is, the end surfaces 94 a and 94b are inclined toward the lower surface 91, and it is more preferablethat the angles be in the range of 30° to 75°. Accordingly, it ispossible to reduce the sizes of the conduction structure and the dropletejecting head 1, and to easily form wiring patterns 28 on the endsurfaces 94 a and 94 b.

In the case of the IC 9 using silicon as the main material, it ispreferable to form the end surfaces 94 a and 94 b on a plane of (1,1, 1) silicon surface orientation. The planarization of the end surfaces94 a and 94 b is enhanced, and the accuracy of the inclination angles ofthe end surfaces 94 a and 94 b can be increased by using the surface asthe end surfaces 94 a and 94 b. Accordingly, when the wiring patterns 28are formed on the end surfaces 94 a and 94 b as described below, thearrangement density can be increased.

Also, in this case, with respect to the reservoir forming substrate 24,it is preferable that the first side wall portions 272 a and 272 b beconfigured on a plane of (1, 1, 1) silicon surface orientation.Accordingly, the end surface 94 a and the first side wall portion 272 aare parallel to each other, and the end surface 94 b and the first sidewall portion 272 b are parallel to each other. Therefore, the endsurface 94 a and the first side wall portion 272 a can be easilypositioned on the same surface, and the end surface 94 b and the firstside wall portion 272 b can be easily positioned on the same surface inthe same manner.

The silicon surface orientation that configures the end surfaces 94 aand 94 b is not limited to the above, and may be, for example, a planeof (1, 0, 0) surface orientation.

The terminals 93 are input/output terminals of the IC 9, and areprovided so as to be exposed to a portion of the upper surface 92 of theIC 9. In addition, in view of the wiring length in a wiring patterndescribed below, it is preferable that the terminals 93 be positionednear the end surfaces 94 a and 94 b. A configuration material of theterminals 93 is not particularly limited, but a metallic material havinglow electrical resistance such as gold or copper can be used.

As illustrated in FIGS. 1, 3, and 4, the wiring patterns 28 are providedin the concave portion 27. The wiring patterns 28 are configured withmultiple lines of linear wiring 280. The wiring 280 is arranged in adistributed manner on the first side wall portions 272 a and 272 bsides. Further, the wiring patterns 28 are not illustrated in FIG. 2.

The multiple lines of wiring 280 on the first side wall portion 272 aside and the multiple lines of wiring 280 on the first side wall portion272 b side are separated from each other in the width direction of theconcave portion 27 (the base substrate 2).

Further, as illustrated in FIG. 3, the adjacent lines of wiring 280 onthe first side wall portion 272 a side are separated from each other inthe longitudinal direction of the concave portion 27, that is, theadjacent lines of wiring 280 are arranged in the longitudinal directionof the concave portion 27 at intervals. That is, the distance betweenthe lines of wiring 280 increases moving toward the bottom portion 271side of the concave portion 27. The short circuiting of the adjacentlines of wiring 280 is prevented on the first side wall portion 272 aside by forming such intervals.

In the same manner, the adjacent lines of wiring 280 on the first sidewall portion 272 b side are arranged in the longitudinal direction ofthe concave portion 27 at intervals. Also, the intervals of the lines ofwiring 280 are also increased moving toward the bottom portion 271 sideof the concave portion 27.

Hereinafter, the configuration of the wiring 280 is more specificallydescribed, but the wiring 280 illustrated in FIG. 4 is representativelydescribed below. In addition, the description in the same manner can beapplied to the other lines of wiring 280.

The wiring 280 illustrated in FIG. 4 is one line of a conducting pathelectrically connecting the upper surface 92 (the terminal 93) of the IC9 to the bottom portion 271 (a portion of the upper electrode film 252)of the concave portion 27 via the end surface 94 a of the IC 9 and thefirst side wall portion 272 a. The IC 9 and the piezoelectric elements25 are electrically connected to each other through the conductionstructure including the wiring 280 so that the droplet ejecting head 1can be operated. Here, the wiring 280 includes a conductive layer 281positioned on the end surface 94 a side and the first side wall portion272 a side, and a plating layer 282 provided so as to be overlapped withthe conductive layer 281 on the opposite side of the end surface 94 a orthe first side wall portion 272 a. The electrical resistance of thewiring patterns 28 can be decreased by forming the wiring 280 to have atwo-layered structure so that the electric power consumption of thedroplet ejecting head 1 can be decreased and the speed of the operationof the piezoelectric element 25 can be increased. Also, since it isdifficult to short circuit the wiring 280, the reliability of thedroplet ejecting head 1 can be improved.

In the wiring 280, the conductive layer 281 illustrated in FIG. 4 can bedivided into four parts. Specifically, the conductive layer 281 can bedivided into a first part 291 provided on the bottom portion 271 of theconcave portion 27 (upper surface of the device substrate 10B), a secondpart 292 provided in the end surface 94 a of the IC 9, a third part 293provided on the upper surface 92 of the IC 9, and a fourth part 294provided on the end surface of the sealing plate 10A (the first sidewall portion 272 a of the concave portion 27). That is, the conductivelayer 281 includes respective parts including the third part 293, thesecond part 292, the fourth part 294, and the first part 291 connectedin this sequence from the terminal 93 side of the IC 9 illustrated inFIG. 4.

Also, the wiring 280 connects the terminal 93 of the IC 9 and the bottomportion 271 of the concave portion 27 corresponding to the terminalportion included in the device substrate 10B (a portion of the upperelectrode film 252) so that the device substrate 10B and the IC 9 arecoupled.

As illustrated above, the end surface 94 a of the IC 9 and the endsurface of the sealing plate 10A (the first side wall portion 272 a ofthe concave portion 27) are positioned on the same surface. Accordingly,when the conductive layer 281 is formed by a photolithographic method,since the second part 292 and the fourth part 294 provided on theinclined surface can easily satisfy the exposure condition, the effectin which the accuracy of the patterning can be easily increased can beobtained. Accordingly, the dimensional accuracy of the wiring 280 isincreased so that the wiring 280 with higher arrangement density can beobtained.

The state in which the end surface 94 a of the IC 9 and the end surfaceof the sealing plate 10A are positioned on the same surface refers to astate in which an angle formed between two surfaces is less than 5°, andthe step of the two surfaces is less than 100 μm.

Meanwhile, the plating layer 282 illustrated in FIG. 4 is provided so asto be overlapped with the conductive layer 281 as described above.Accordingly, the conductive layer 281 can be reinforced, thecross-sectional area of the wiring 280 can be enlarged, and theelectrical resistance can be decreased. In addition, the plating layer282 may not necessarily be overlapped with the entire conductive layer281. For example, a portion of the plating layer 282 may be defected aslong as the plating layer 282 is not electrically cut.

The plating layer 282 is formed by various plating methods. In theplating method, a film can be formed by depositing a metallic componenton a ground portion. Therefore, the plating layer 282 can be naturallygrown in a linear shape by forming the conductive layer 281 in a linearshape in advance. In other words, while maintaining the shape of theconductive layer 281 on the ground portion, the plating layer 282 can beformed. As a result, if the wiring 280 is to be formed at high density(if the fine wiring pattern is formed at a narrow pitch), the correctmanufacturing of the wiring 280 can be easily performed.

Further, since the wiring 280 has a two-layered structure as describedabove, and one of the two layers is the plating layer 282, the thicknessthereof can be easily adjusted. Therefore, it is easy to cause thewiring 280 to be disposed at high density and to have low electricalresistance at the same time so that the electric power consumption ofthe droplet ejecting head 1 can be decreased, and the speed of theoperation of the piezoelectric elements 25 can be increased at the sametime.

In other words, it becomes easy to cause the wiring 280 to be fine bycausing the wiring 280 to have a two-layered structure. If the wiring280 has the two-layered structure, even if the line width is the same,the increase in the electrical resistance can be easily suppressed, andtherefore it becomes easy to cause the wiring 280 to be fine. In thisregard, it is possible to cause the wiring 280 to be disposed at highdensity.

In addition, the plating layer 282 may be provided, if necessary. Forexample, if the conductive layer 281 is sufficiently thick, and does notneed to be reinforced, the plating layer 282 may be omitted.

In the droplet ejecting head 1 according to the first embodiment, the IC9 is mounted in a state in which the terminal 93 of the IC 9 ispositioned on the opposite side of the mounting surface, that is, aface-up state. Therefore, compared with the case in which the IC 9 ismounted in the face-down state, even if the IC 9 is mounted on the basesubstrate 2, the connection portion of the terminal 93 and the wiring280 can be directly seen. As a result, there is an advantage in that theinspection operation of the connection state of the terminal 93 and thewiring 280 can be easily performed.

Further, all parts of the conductive layer 281 from the first part 291to the fourth part 294 can be seen in the direction A in FIG. 1.Therefore, there is an advantage in that the inspection operation ofthese parts can be easily performed, the conductive layer 281 can beeasily formed by various film forming methods described below, and thethickness of the conductive layer 281 can be easily uniformized.

Meanwhile, the sealing plate 10A according to the first embodimentincludes a conductive layer 246 provided on the upper surface of thereservoir forming substrate 24. The conductive layer 246 is provided, ifnecessary. Therefore, the conductive layer 246 may be omitted, but mayhave electrical wiring formed by patterning. That is, an arbitraryelectronic circuit may be formed on the sealing plate 10A. In this case,in the fourth part 294, the electronic circuit formed on the sealingplate 10A can be connected to the IC 9 or the piezoelectric elements 25by securing conductivity between the conductive layer 246 and the wiring280. In other words, the IC 9, the electronic circuit of the sealingplate 10A, and the piezoelectric elements 25 can be three-dimensionallyconnected through the wiring 280.

The conductive layer 246 and the wiring 280 may be connected by usingall the wiring 280, or by selectively using a certain portion of wiring280. That is, in the wiring pattern 28, in addition to the wiring 280that electrically connects the piezoelectric elements 25 and the IC 9,the wiring 280 that connects the conductive layer 246 and thepiezoelectric elements 25, the wiring 280 that connects the IC 9 and theconductive layer 246, and the like are included.

The conductive layer 281 or 246 includes a conductive material such asNi, Pd, Au, Al, Ti, Ti—W, or Cu, singly or as a compound.

Further, the conductive layer 281 or 246 may have a single layerstructure, or a stacked structure in which a plurality of layers areoverlapped. In the latter case, it is preferable that a ground-sidelayer (layer far from the plating layer 282) be configured with aNi—Cr-based alloy, and a layer on the plating layer 282 side beconfigured with Au. Accordingly, both the adhesion and the conductivityof the conductive layer 281 can be achieved.

Meanwhile, the plating layer 282 has conductivity, and is configuredwith a material that can be deposited through a plating method. Examplesof the material include Ni, Cu, Au, Pd, Co, Sn, and Ag. In addition, amaterial that can be codeposited through the plating method may beincluded in the plating layer 282. Examples of the correspondingmaterial include P, B, and Bi.

The conduction structure according to the first embodiment that isconfigured to conduct the IC 9 and the piezoelectric element 25 via thewiring pattern 28 is advantageous in that it is possible to cause thewiring pattern 28 to be disposed at high density and to cause easymanufacture of the wiring pattern 28. In addition, since thecorresponding conduction structure is configured so as to construct thewiring pattern 28 by using the inclination surface, there is anadvantage in that highly accurate machining such as thephotolithographic method can be applied. Therefore, when the wiringpattern 28 is constructed so that substrates are joined to each other inthe thickness direction of the stacked substrates, the conductionstructure according to the first embodiment is highly advantageous inthat it is possible to cause the wiring pattern 28 to be disposed athigh density and to cause easy manufacture of the wiring pattern 28.

If necessary, the plurality of sealing plates 10A may be interposedbetween the IC 9 and the device substrate 10B. Also, instead of thesealing plate 10A, another member may be interposed. In this case, it ispossible to achieve the advantages described above.

The number of ICs 9 mounted on one droplet ejecting head 1 is notparticularly limited, and may be greater or less than that according tothe first embodiment.

Meanwhile, among the respective ICs 9, the wiring pattern 28 formed withthe wiring 280 including the conductive layer 281 and the plating layer282 is constructed on the end surface on the opposite side to the endsurface 94 a in which the wiring pattern 28 is constructed. Theconfiguration of the wiring 280 (the wiring pattern 28) described hereis the same as that of the wiring 280 (the wiring pattern 28) describedabove. Accordingly, the wiring 280 provided on the end surface on theopposite side to the end surface 94 a has the same advantage asdescribed above. That is, all the wiring 280 connect the terminals 93 ofthe IC 9 and the conductive layer 246. If it is possible to cause thewiring 280 to be disposed at high density and in a highly reliablemanner, it is possible to cause the droplet ejecting head 1 to besmaller and more reliable.

In addition, in the drawings, it is illustrated that the wiring 280constructed in the end surfaces of the IC 9 is electrically connected toeach other via the conductive layer 246, but it is illustrated just forthe convenience for illustration, and the wiring 280 may be electricallyinsulated.

Method of Manufacturing Conduction Structure

A method of manufacturing a droplet ejecting head (the droplet ejectinghead 1 illustrated in FIG. 1) including an embodiment of a method ofmanufacturing the conduction structure according to the invention isdescribed. Also, in FIGS. 5A to 6C, a portion of the droplet ejectinghead 1 is illustrated, and the other portion is omitted.

The method of manufacturing the droplet ejecting head 1 includes a stepof bonding the IC 9, the sealing plate 10A, and the device substrate10B, a step of forming a metallic film, a step of obtaining theconductive layer 281 by patterning the metallic film, and a step ofdepositing the plating layer 282 on the conductive layer 281 by aplating method. Hereinafter, the respective steps are sequentiallydescribed.

[1] First, the reservoir forming substrate 24 as illustrated in FIG. 5Ais prepared. The reservoir forming substrate 24 is formed, for example,by performing processing such as anisotropic etching, on an unprocessedbase material. According to the anisotropic etching method, it ispossible to easily form an angle between the processed surface and themain surface of the base material as designed. Therefore, it is possibleto easily perform the processing into a desired shape. Specifically,after forming the first side wall portion 272 a of the concave portion27, it is possible to form the inclination angle to be close to theshape as designed, and it is possible to particularly enhance thedimensional accuracy of the reservoir forming substrate 24.

If the anisotropic etching is performed, for example, a SiO₂ film havinga thickness of about 700 nm is formed on an outer surface of the basematerial by performing thermal oxidation on the base material.Subsequently, patterning is performed by applying a resist on bothsurfaces of the base material. Then, a portion of SiO₂ film is removedby immersing the base material in hydrofluoric acid so that the outersurface of the base material is exposed. Then, after separating theresist, the base material is immersed in a KOH solution having aconcentration of about 35% so that the concave portion 27, thepiezoelectric element receiving chambers 245, and the like are formed onthe base material. Accordingly, the reservoir forming substrate 24 isobtained. Subsequently, after the SiO₂ film is etched with thehydrofluoric acid, the thermal oxidation is performed again on thereservoir forming substrate 24, so as to insulate the outer surface ofthe reservoir forming substrate 24.

Subsequently, as illustrated in FIG. 5B, the conductive layer 246 isformed on the upper surface of the reservoir forming substrate 24.Thereafter, if necessary, the conductive layer 246 is patterned.Accordingly, it is possible to form the electronic circuit in theconductive layer 246. In addition, the method of forming and patterningthe conductive layer 246 is the same as the method of forming andpatterning the conductive layer 281 described below.

As described above, the sealing plate 10A can be obtained.

Subsequently, the device substrate 10B as illustrated in FIG. 5C isprepared. The device substrate 10B includes the flow channel formingsubstrate 22, the diaphragm 23, the plurality of piezoelectric elements25, and the like as described above. Also, the sealing plate 10A and thedevice substrate 10B are bonded via the adhesive layer 11. In addition,the flow channel forming substrate 22 is formed after bonding thesealing plate 10A and the device substrate 10B.

The composition of an adhesive agent configuring the adhesive layer 11is not particularly limited, and any kind of adhesive agent can be used.However, it is preferable to use an adhesive agent using a thermosettingresin as the main component. Since such an adhesive agent hascomparatively high thermal resistance and chemical resistance, theadhesive layer 11 that is not easily deteriorated during platingtreatment can be formed. Specifically, an epoxy-based adhesive agent, aurethane-based adhesive agent, a silicone-based adhesive agent, anolefin-based adhesive agent, and the like may be included.

The nozzle substrate 21 is bonded to the lower surface of the devicesubstrate 10B. Also, though it is not illustrated in FIG. 5C, thecompliance substrate 26 and the like are formed. As described above, thebase substrate 2 as illustrated in FIG. 5C can be obtained.

Subsequently, as illustrated in FIG. 6A, the IC 9 is bonded to the uppersurface 265 of the base substrate 2 via the adhesive layer 14. At thispoint, the arrangement of the IC 9 is adjusted so that the first sidewall portion 272 a of the concave portion 27 and the end surface 94 a ofthe IC 9 are positioned on the same surface. In the same manner, thearrangement of the IC 9 is adjusted so that the first side wall portion272 b of the concave portion 27 and the end surface 94 b of the IC 9 arepositioned on the same surface.

The composition of the adhesive agent that configures the adhesive layer14 is not particularly limited, and is the same as the composition ofthe adhesive agent that configures the adhesive layer 11 describedabove.

[2] Subsequently, a metallic film is formed on the entire surface of thebase substrate 2 to which the IC 9 is bonded. The metallic film isformed through various film forming methods such as a vacuum evaporationmethod, a sputtering method, a CVD method, a plating method, and thelike. Among these, the sputtering method is preferably used. Accordingto the sputtering method, since it is possible to form a metallic filmhaving high adhesive properties at a comparatively low temperature, theheat effect on the base substrate 2 followed by the film formation canbe suppressed to the minimum, and can contribute to the realization ofthe droplet ejecting head 1 with high accuracy. Also, since the controlof the film thickness is comparatively easy, it is possible to obtainthe metallic film which is highly uniform in thickness. Finally, it ispossible to enhance the accuracy in patterning the conductive layer 281,and to contribute to the formation of highly dense wiring 280. Also, themetallic film is provided to form the conductive layer 281, and may havea single layer or multiple layers as described above.

Subsequently, the resist is formed on the obtained metallic film. Then,the resist is patterned by a photolithography (exposure or developing)method.

Subsequently, an etching treatment is performed on the metallic film. Inthe case of wet etching, iodine-based etchant, nitric acid-basedetchant, hydrochloric acid-based etchant, and hydrogen peroxide-basedetchant are preferably used as the etchant.

Subsequently, the resist is separated. Accordingly, the conductive layer281 illustrated in FIG. 6B can be obtained by patterning the metallicfilm.

In addition, in view of forming the metallic film, it is preferable thatthe right side end portion of the adhesive layer 11 in FIG. 4 be matchedwith the lower end portion of the reservoir forming substrate 24, orslightly protrude from the lower end portion of the reservoir formingsubstrate 24 to the right side. Accordingly, when the metallic film isformed, it is unlikely that the metallic film will be disrupted betweenthe sealing plate 10A and the device substrate 10B, and the reliabilityof the conductive layer 281 can be improved.

In the same manner, it is preferable that, among the end portions of theadhesive layer 14 in FIG. 4, the end portion positioned on the concaveportion 27 side be matched with the lower end portion of the end surface94 a of the IC 9, or slightly protrude from the lower end portion of theend surface 94 a to the concave portion 27 side. Accordingly, when themetallic film is formed, it is unlikely that the metallic film will bedisrupted between the IC 9 and the sealing plate 10A, and thereliability of the conductive layer 281 can be improved.

When the adhesive layers 11 and 14 protrude, it is preferable that theprotrusion amount be less than the deviation amount between the endsurface 94 a and the first side wall portion 272 a. Accordingly, itbecomes more unlikely that the metallic film will be disrupted, and thereliability of the conductive layer 281 can be improved.

Subsequently, the plating layer 282 is deposited on the conductive layer281 by a plating method. Accordingly, the wiring 280 (the wiringpatterns 28) illustrated in FIG. 6C is formed. Also, the dropletejecting head 1 and the conduction structure included therein can beobtained.

It is preferable that the plating method be an electrolytic platingmethod, but an electroless plating method can also be preferably used.According to the electroless plating method, metal is selectivelydeposited to the conductive layer 281, and the plating layer 282 can beeasily formed. Further, inserting an electrode therein is not necessary.Also, even if the concave portion 27 exists, if plating solution ispermeated therein, the plating can be performed. Therefore, theelectroless plating method can be appropriately applied particularly tothe form of the droplet ejecting head 1.

Also, in the case of the plating method, since the plating layer 282 isisotropically deposited from the conductive layer 281, the plating layer282 grows not only in the thickness direction of the conductive layer281, but also in the width direction. At this point, if the separationdistance between the adjacent conductive layers 281 is short, a shortcircuit may occur. On the contrary, according to the first embodiment,after the IC 9, the sealing plate 10A, and the device substrate 10B arebonded together as described above, the conductive layer 281 is formed,and then the plating layer 282 is formed. Therefore, since theconductive layer 281 is constructed in advance in an area in which thewiring 280 is to be formed, the wiring do not have to be joined by theplating layer 282. Accordingly, the thickness of the plating layer 282is sufficient if it is the thickness with which the conductive layer 281can be reinforced, and it does not have to be unnecessarily thick.Accordingly, even if the separation distance between the adjacentconductive layers 281 is small, it is possible to form the plating layer282. As a result, it is possible to cause the wiring 280 to be disposedat high density, and to have low electrical resistance at the same time.

In addition, according to the first embodiment, after the conductivelayer 281 is formed, the plating layer 282 is deposited thereon.Therefore, it is possible to cause the fineness of the obtained wiring280 to be almost the same as the fineness of the conductive layer 281.Accordingly, since it is possible to obtain the highly fine conductivelayer 281 by forming the conductive layer 281, for example, by thephotolithographic method, it is possible to obtain the highly finewiring 280 as a result. According to the same principle, it is possibleto cause the wiring 280 to be disposed at high density and to reduce thesize of the droplet ejecting head 1.

The droplet ejecting head 1 obtained as described above has an advantagein that it is possible to easily reduce the size thereof by causing thewiring 280 to be disposed at high density and it is possible to easilyobtain the enhancement of the operation performance (for example, speedimprovement) and the improvement of reliability by causing the wiring280 to have low electrical resistance.

In addition, the first embodiment is an example in which one reservoirforming substrate 24 is formed with one sheet of base material, but theinvention is not limited thereto. However, one droplet ejecting head 1may be manufactured by forming a plurality of reservoir formingsubstrates 24 with one sheet of base material and then performing theseparating operation.

Printing Apparatus

The printing apparatus 100 including the droplet ejecting head 1 isdescribed.

The printing apparatus 100 illustrated in FIG. 7 is a printing apparatusperforming printing on the recording medium 200 by an ink jet method.The printing apparatus 100 includes an apparatus main body 50, recordinghead units 20A and 20B on which the droplet ejecting head 1 is mounted,ink cartridges 30A and 30B that supply the ink 300, a carriage 40 thattransports the recording head units 20A and 20B, a moving mechanism 70that moves the carriage 40, and the carriage shaft 60 that movablysupports (guides) the carriage 40.

The ink cartridge 30A can be detachably mounted on the recording headunit 20A and supply the ink 300 (black ink composition) to the recordinghead unit 20A in the mounted state.

The ink cartridge 30B can be also detachably mounted on the recordinghead unit 20B, and supply the ink 300 (color ink composition) to therecording head unit 20B in the mounted state.

The moving mechanism 70 includes a driving motor 701, and a timing belt702 coupled to the driving motor 701. Also, it is possible to move thecarriage 40 in the direction of the carriage shaft 60 together with therecording head units 20A and 20B by transporting the driving force(torque) of the driving motor 701 to the carriage 40 via the timing belt702.

A platen 80 is provided in the apparatus main body 50 to the lower sideof the carriage shaft 60 in the axial direction. The recording medium200 fed by a feeding roller (not illustrated) or the like is transportedto the platen 80. Then, printing is performed by ejecting the ink 300onto the recording medium 200 on the platen 80.

According to the embodiment of the invention, since it is possible toachieve the reduction of the size of the droplet ejecting head 1, andthe improvement of the reliability, it is possible to achieve thereduction of the size and the improvement of the reliability of theprinting apparatus 100.

Second Embodiment

FIG. 8 is an enlarged cross-sectional view illustrating a part of adroplet ejecting head to which the conduction structure according to thesecond embodiment of the invention is applied (droplet ejecting headaccording to second embodiment of the invention). Hereinafter, forconvenience of description, upper sides of FIG. 8 are referred to as“up” or “upper”, and lower sides thereof are referred to as “under” or“lower”.

Hereinafter, the second embodiment is described, but differences fromthe embodiment described above are mainly described below, and the samematters are omitted in the description.

The droplet ejecting head 1 according to the second embodiment is thesame as the droplet ejecting head 1 according to the first embodimentexcept that the conductive layer 246 provided on the upper surface ofthe reservoir forming substrate 24 extends to the first side wallportion 272 a side of the concave portion 27. Also, in FIG. 8,configurations which are the same as those in the first embodimentdescribed above are denoted by the same reference numerals.

The conductive layer 246 illustrated in FIG. 8 extends from the uppersurface of the reservoir forming substrate 24 to the first side wallportion 272 a connected thereto. Also, the terminal end of theconductive layer 246 is positioned in the middle of the first side wallportion 272 a. The extended part of the conductive layer 246 is referredto as an extended portion 246 a.

It is possible to more securely connect the conductive layer 246 and theconductive layer 281 by providing the extended portion 246 a. That is,it is possible to cause the conductive layer 246 and the conductivelayer 281 to come into contact with each other in a wider area on thefirst side wall portion 272 a by providing the extended portion 246 a,and therefore it is possible to reduce the connection resistance.Therefore, it is possible to improve the reliability of the electricconnection between the conductive layer 246 and the conductive layer281.

In addition, according to the second embodiment, it is also possible toobtain effects and the results which are the same as in the firstembodiment described above.

Third Embodiment

FIG. 9 is an enlarged cross-sectional view illustrating a part of adroplet ejecting head to which a conduction structure according to athird embodiment of the invention is applied (droplet ejecting headaccording to third embodiment of the invention). Hereinafter, forconvenience of description, upper sides of FIG. 9 are referred to as“up” or “upper”, and lower sides thereof are referred to as “under” or“lower”.

Hereinafter, the third embodiment is described, but differences from theembodiments described above are mainly described below, and the samematters are omitted in the description.

The droplet ejecting head 1 according to the third embodiment is thesame as the droplet ejecting head 1 according to the first and secondembodiments except that the end surface 94 a of the IC 9, and the firstside wall portion 272 a of the concave portion 27 are deviated from eachother. Also, in FIG. 9, configurations which are the same as those inthe first embodiment described above are denoted by the same referencenumerals.

The IC 9 illustrated in FIG. 9 is arranged so that the end surface 94 athereof is deviated to recess from an extended line of the first sidewall portion 272 a of the concave portion 27 to the left side of FIG. 9.As a result of the arrangement described above, a step is formed betweenthe end surface 94 a and the first side wall portion 272 a. In FIG. 9,the upper surface 265 of the sealing plate 10A is exposed between theend surface 94 a and the first side wall portion 272 a, and this becomesthe step.

Accordingly, if the metallic film is formed on such portion and ispatterned, the conductive layer 281 formed with five parts is obtained.Specifically, a fifth part 295 provided on the upper surface 265 of thesealing plate 10A is added between the second part 292 and the fourthpart 294 illustrated in FIG. 4. Accordingly, in the conductive layer 281illustrated in FIG. 9, the third part 293, the second part 292, thefifth part 295, the fourth part 294, and the first part 291 aresequentially connected from the upper side.

The deviation amount between the end surface 94 a and the first sidewall portion 272 a is appropriately set according to the size of thedroplet ejecting head 1, and is not particularly limited. However, forexample, the deviation amount is preferably in the range ofapproximately 50 μm to 2000 μm, and more preferably in the range ofapproximately 100 μm to 1000 μm. In this range, it is possible to formthe metallic film without interruption while suppressing the variationof the film thickness.

The conductive layer 281 can cause the connection resistance between theconductive layer 281 and the conductive layer 246 to be smaller in orderto securely connect the fifth part 295 and the conductive layer 246.Accordingly, it is possible to improve the reliability of the electricconnection between the conductive layer 246 and the conductive layer281. Particularly, if the electronic circuit is formed by patterning theconductive layer 246, it is advantageous from the view point of theoperation stability of the electronic circuit or the like.

Further, since the conduction structure described above can be formedsimply by deviating the IC 9, there is an advantage in thatmanufacturability is particularly high. Also, even if the conductivelayer 246 is not extended as in the second embodiment, manufacturabilityis high from the view point of the possibility of the electricconnection between the conductive layer 246 and the conductive layer281.

In addition, according to the third embodiment, it is also possible toobtain the effects and the results which are the same as in the firstand second embodiments described above.

Fourth Embodiment

FIG. 10 is an enlarged cross-sectional view illustrating a part of asemiconductor apparatus to which the conduction structure according to afourth embodiment of the invention is applied. Hereinafter, forconvenience of description, upper sides of FIG. 10 are referred to as“up” or “upper”, and lower sides thereof are referred to as “under” or“lower”.

Hereinafter, the fourth embodiment is described, but differences fromthe embodiments described above are mainly described below, and the samematters are omitted in the description. Also, in FIG. 10, configurationswhich are the same as those in the first to third embodiments describedabove are denoted by the same reference numerals.

A semiconductor apparatus 1000 having the conduction structure accordingto the fourth embodiment includes a semiconductor package substrate 95,a first semiconductor chip 9A mounted thereon, and a secondsemiconductor chip 9B further stacked thereon. The semiconductorapparatus 1000 is operated as a stacking-type semiconductor device byconnecting a terminal (not illustrated) provided on the lower surface ofthe package substrate 95 to the electric circuit. In addition, thepackage substrate 95, the first semiconductor chip 9A, and the secondsemiconductor chip 9B according to the fourth embodiment all have aplate shape that expands in the horizontal direction of FIG. 10.Therefore, in the description according to the fourth embodiment, amongthe two main surfaces included in each of the package substrate 95, thefirst semiconductor chip 9A, and the second semiconductor chip 9B, amain surface positioned on the upper side of FIG. 10 is referred to asan “upper surface”, and the other main surface positioned on the lowerside is referred to as a “lower surface”.

The package substrate 95 includes an insulation substrate 951 and aconductive layer 952. As respective configuration materials of theinsulation substrate 951 and the conductive layer 952, configurationmaterials used in the well-known package substrate are used. Also, aportion of the conductive layer 952 included in the package substrate 95corresponds to the “terminal portion”.

In addition, the first semiconductor chip 9A is bonded to the uppersurface of the package substrate 95 via an adhesive layer 14A. The firstsemiconductor chip 9A has the same configuration as the IC 9 accordingto the first embodiment.

In the first semiconductor chip 9A, a lower surface 91A and an uppersurface 92A are parallel to each other, and the lower surface 91A isbonded to the upper surface of the package substrate 95 so as to besubstantially parallel to each other.

Meanwhile, end surfaces 941 and 941 of the first semiconductor chip 9Aare inclined respectively to the lower surface 91A and the upper surface92A, and continue to the lower surface 91A and the upper surface 92A.The end surfaces 941 and 941 have the same configuration as the endsurface 94 a of the IC 9 according to the first embodiment.

Also, the first semiconductor chip 9A includes the terminals 93 providedto be exposed to the upper surface 92A thereof. It is possible tooperate the first semiconductor chip 9A by connecting the terminals 93to the package substrate 95. That is, the conductive layer 281 isprovided on the end surface 941 of the first semiconductor chip 9A, andconnects a terminal portion (the conductive layer 952) of the packagesubstrate 95 and the terminal 93 of the first semiconductor chip 9A sothat the package substrate 95 and the first semiconductor chip 9A arecoupled.

The second semiconductor chip 9B is bonded to the upper surface of thefirst semiconductor chip 9A via the adhesive layer 14B. The secondsemiconductor chip 9B also has the same configuration as that of the IC9 according to the first embodiment.

The configuration of the second semiconductor chip 9B is the same asthat of the first semiconductor chip 9A except that the sizes of a lowersurface 91B and an upper surface 92B are respectively smaller than thosein the first semiconductor chip 9A.

Meanwhile, end surfaces 942 and 942 of the second semiconductor chip 9Bare inclined respectively to the lower surface 91B and the upper surface92B, and are continued to the lower surface 91B and the upper surface92B. The end surfaces 942 and 942 also have the same configuration asthat of the end surface 94 a of the IC 9 according to the firstembodiment.

Also, the second semiconductor chip 9B includes the terminals 93provided so as to be exposed to the upper surface 92B. It is possible tooperate the second semiconductor chip 9B by connecting the terminals 93to the package substrate 95.

Here, the first semiconductor chip 9A and the second semiconductor chip9B are arranged so that the end surface 941 and the end surface 942 aredeviated from each other in the same manner as in the third embodiment.Also, the semiconductor apparatus 1000 includes the conductive layer 281and the plating layer 282 in the same manner as in the conductionstructure according to the third embodiment. Specifically, theconductive layer 281 illustrated in FIG. 10 includes the third part 293provided on the upper surface 92B of the second semiconductor chip 9B,the second part 292 provided on the end surface 942, the fifth part 295provided on the upper surface 92A of the first semiconductor chip 9A,the fourth part 294 provided on the end surface 941, and the first part291 provided on the upper surface of the package substrate 95.

The wiring 280 including the conductive layer 281 and the plating layer282 can be disposed at high density, and have low electrical resistanceat the same time as in the respective embodiments described above.Accordingly, the semiconductor apparatus 1000 having the conductionstructure including the wiring 280 (the wiring pattern 28) can easily bereduced in size and have high reliability.

In addition, according to the fourth embodiment, it is possible toachieve the effects and the results as described in the first to thirdembodiments described above.

In addition, the number of stacked layers of the semiconductor chip isnot limited to 2, and may be 3 or more.

In addition, it is possible to obtain the small and highly reliableelectronic apparatus by mounting the semiconductor apparatus 1000 on anelectronic apparatus.

As the electronic apparatus, for example, a personal computer (mobilepersonal computer), a cellular phone, a digital still camera, a lap toppersonal computer, a television, a video camera, a video tape recorder,a car navigation apparatus, a pager, an electronic organizer (includingone with a communication function), an electronic dictionary, acalculator, an electronic gaming apparatus, a word processor, a workstation, a video phone, a security television monitor, electronicbinocular, a POS terminal, medical equipment (for example, an electronicthermometer, a sphygmomanometer, a blood sugar meter, anelectrocardiographic apparatus, an ultrasonic diagnosis apparatus, andan electronic endoscope), a fish finder, various measuring apparatuses,instruments (for example, instruments for vehicles, planes, and ships),and a flight simulator are included.

In the above, a conduction structure, a method of manufacturing aconduction structure, a droplet ejecting head, and a printing apparatusaccording to the invention are described with reference to theembodiments in the drawings. However, the invention is not limitedthereto, and the respective units that configure the conductionstructure, the droplet ejecting head, and the printing apparatus can besubstituted with any configurations that can exhibit the same functions.In addition, certain configurations can also be considered.

In addition, in the first to third embodiments, the device substrate isused as an example of the first substrate, the IC is used as an exampleof the second substrate, and the sealing plate is used as an example ofthe third substrate. In addition, in the fourth embodiment, the packagesubstrate is used as an example of the first substrate, andsemiconductor chips are used as examples of the second substrate and thethird substrate. However, the invention is not limited to these, and thefirst to third substrates may be substrates respectively having certainfunctions.

In addition, the conduction structure, the method of manufacturing theconduction structure, the droplet ejecting head, and the printingapparatus according to the invention may be obtained by combining two ormore arbitrary configurations (characteristics) according to therespective embodiments.

Also, the droplet ejecting head (printing apparatus) is configured toperform printing by ejecting ink as droplets onto a recording mediumsuch as printing paper. The invention is not limited thereto, and forexample, a liquid crystal display device can be manufactured by ejectinga liquid crystal display device forming material as droplets, an organicEL display device (organic EL apparatus) can be manufactured by ejectingthe organic EL forming material as droplets, and a circuit substrate canbe manufactured by ejecting a wiring pattern forming material asdroplets and forming a wiring pattern of an electric circuit.

The entire disclosure of Japanese Patent Application No. 2014-23736,filed Feb. 10, 2014 is expressly incorporated by reference herein.

What is claimed is:
 1. A droplet ejecting head comprising: a conductionstructure comprising: a first substrate that has a main surface, andincludes a terminal portion for performing electric connection; a secondsubstrate that has a main surface and an end surface adjacent to themain surface of the second substrate in a non-parallel manner, whereinthe end surface of the second substrate is a single plane, the secondsubstrate being bonded so that the main surface of the second substrateopposed to the main surface of the first substrate and including aterminal portion for performing electric connection; a conductive layerof which at least a portion is provided on the end surface of the secondsubstrate so as to connect the terminal portion of the first substrateand the terminal portion of the second substrate; a third substrate thathas a main surface and an end surface adjacent to the main surface ofthe third substrate in a non-parallel manner, wherein the end surface ofthe third substrate is a single plane, the third substrate beingprovided between the first substrate and the second substrate, whereinthe terminal portion of the second substrate extends to the end surfaceof the second substrate, wherein the end surface of the second substrateis configured with a plane of (1, 1, 1) with respect to the orientationof the main surface of the second substrate, wherein the terminalportion of the first substrate is provided on the main surface of thefirst substrate, wherein the terminal portion of the second substrate isprovided on the main surface of the second substrate, and wherein theconductive layer includes a first part provided on the main surface ofthe first substrate, a second part that is provided on the end surfaceof the second substrate and is electrically connected to the first part,and a third part that is provided on the main surface of the secondsubstrate and is electrically connected to the second part, wherein theconductive layer includes a fourth part that is provided on the endsurface of the third substrate, and is electrically connected to both ofthe first part and the second part, wherein the end surface of thesecond substrate and the end surface of the third substrate arepositioned in a deviated manner, wherein the conductive layer furtherincludes a fifth part that is provided on the main surface of the thirdsubstrate, and is electrically connected to both the second part and thefourth part, and wherein the third substrate includes an electriccircuit electrically connected to the fifth part.
 2. The dropletejecting head according to claim 1, wherein an angle formed between themain surface of the second substrate and the end surface of the secondsubstrate is greater than 0° and less than 90°.
 3. The droplet ejectinghead according to claim 1, further comprising: a plating layer that isoverlapped with at least a portion of the conductive layer.
 4. Thedroplet ejecting head according to claim 1, wherein the second substrateis made of silicon as a main material.
 5. The droplet ejecting headaccording to claim 1, wherein the end surface of the second substrateand the end surface of the third substrate are positioned on the samesurface.
 6. The droplet ejecting head according to claim 1, wherein thethird substrate includes an electric circuit electrically connected tothe fifth part.
 7. A printing apparatus comprising: the droplet ejectinghead according to claim 1.